The impact of mask photoresist develop on critical dimension parameters

As the tolerances for photomask Critical Dimension (CD) become smaller, more focus has been placed on all processes and their contribution to final mask CD. One key contributor to final mask feature dimensions is the resist develop process and it is the focus of this work. We have studied different resist develop methods to determine optimum process conditions for 45 nm critical photomasks. In searching for the optimum conditions, special consideration was made to study the influence of pattern density effects. We focused on variations in the develop nozzle. Results of the nozzles' impact on pattern density and long range pattern density effects will be presented, for both positive and negative chemically-amplified resists. A characterization of the repeatability of the processes will be presented as well.